Nonferrous metal burnishing composition and burnishing process



Patented Jan. 30, 1951 UNITED STATES PATENT OFFICE NONFERROUS METAL BURNISHING COMPO- SITION AND BURNISHING PROCESS No Drawing. Application April 19, 1947, Serial No. 742,736

8 Claims. (Cl. 51-282) pegs, wood chips, etc. It is the general objective 10 of such a burnishing treatment to perform two functions: first, the removal of any tarnish on the non-ferrous metal surface, and secondly the lusterizing, brightening or polishing of such surface, without causing the redeposition of a tarnish.

Heretofore such burnishing metal treatments have been carried out in an aqueous solution containing soap and sodium cyanide, or one containing a wetting agent such as ispropyl naphthalene sulfonate. The burnishing treatments accomplished by the use of such aqueous solutions however, have been found to be deficient in that they wouldnot accomplish both of the desired functions of removing tarnish and brightening of the metal surface without tarnish redeposition.

I have discovered that this dual function objective can be attained by performing the burnishing treatment in an aqueous solution containing a synthetic organic wetting agent, preferably one derived from a long chain alkoxy compound, and containing an alkylenepolyamine. Only very small amounts of such wetting agent and alkylenepolyamine need be present in the aqueous solution to achieve the desired result. Thus ODDS-0.05% by weight (all percentages herein given by weight unless otherwise specified) of alkylenepolyamine and 0.05-0.1% of long chain alkoxy-derivative wetting agent, represent suitable and operative range concentrations of these ingredients.

In making up a composition suitable for use in the burnishing operation, i. e., by further dilution with water, a composition consisting of 5-20 parts by weight of wetting agent and 5-2 parts of alkylenepolyamine, represents preferred range proportions. When such composition is to bemade in liquid form, as a concentrated stock solu- .tion for use by the burnishing operator, then water may be added to the'last given range proportions of ingredients in a quantity suflicient to make a total of 100 parts. The long chain alkoxy-derivative wetting agent 2 Cerfak N-lOO" and Cerfak N-lOl (a sulionated condensation product of an alcohol and a higher fatty acid) "Arctic Syntex M" (a sodium salt of a sulfonated glycerol-higher fatty acid monoester corresponding to the chemical formula:

RCOOCHzCHOHCI-IzOSOsNa where RCOO represents a mixed coconut oil-fatty acid radical); Alrosol (an alkanolamine-higher fatty acid condensation product); "Duponol ME," dry and Duponol G" (the sodium salts of sulfated higher alkanols, principally lauryl alcohol).

As the alkylenepolyamine ingredient of my composition, it has been determined that ethylene diamine, propylene diamine and triethylene tetramine are most suitable and to be preferred.

Monoethanolamine is preferably added to the composition of my invention as a stabilizing and an alkaline pH control agent, and in an amount equal to one-half that of the wetting agent; or in a range proportion of 0.025-0.05% concentration in the final burnishing solution.

In order to determine the operability and emciency of the compositions of my invention, they have been subjected to a tarnish removal test" and luster test, the conditions and specifications of which are as follows:

Tarm'sh removal test Specimens of brass plate, measuring 3" x 1 with on each of the 1 width ends bent over at right angles, are placed in a rubber lined, closed tumbling barrel together with 50 lbs. of diameter steel balls. This tumbling barrel, mounted on a horizontal axis, is driven at a speed of 30 R. P. M. The specimen brass plates before charging into the barrel, are first degreased with an alkaline detergent, and then given a tarnish by the following procedure:

1. Immersed in a 2% caustic soda solution at 35 C. and subjected to a 2.8 ampere current for 1 minute, with the brass specimen as the anode.-

2. Subjected to the same electrolytic treatment in the same caustic soda solution for 1 minute, but at a current of. 0.25 ampere.

3. Removed from caustic soda solution, held in the air for 1 minute and rinsed oil with water.

The burnishing composition is made up at a concentration of 1 liquid ounce per gallon in tap water of medium hardness (approximately 7 grain hardness) in an amount to make two liters ingredient of my composition is commercially of solution which is then added to the tumbling available under various trade names, such as barrel whereupon the tarnished brass specimens,

3 together. with the steel balls, are tumbled for a one-half hour period. The light reflectance,

measured by means of a reflectometer, of the tar- The brass plate specimens of the same didiamine, not only was there over twice the increase in reflectance in the tarnish removal test, but there was a substantial reflectance increase in the luster test, with no redeposition of tarnish.

A stock solution was made up consisting of 10% of the same wetting agent as employed in the results shown in Table I, plus 5% monoethanolamine, and varying percentage proportions of different alkylenepolyamines. These solutions were then similarly tested and with the following results:

Table II Tarnish Removal Test Luster Test Altnine Agdltlmtl tg710%MWet- P e Initial Final Reflect- Initial Final Reflect- Appearance ethanomm'ne Sohmon Reflect- Reilectance Beilect- Reflectancc ance ence Increase anee ence Increase None 20. 39. 19.5 44 0 61.0 17. 0 Tamished.

Ethylene Diamine W7}, 44. 5 75. 0 30. 5 Bright. Ethylene Diamine 42. 5 7i. 5 29.0 Do. Ethylene Diaminv 43.0 74. 5 31. 5 Do. Ethylene Dienliilc 2% 48.0 80.5 32. 5 Do. Propylene Dlnlnine 17.5 66.0 48. 5 45.0 81.0 36.0 Do. 'lriethylene 'Ietramine 2%. 42.0 75. 5 32. 5 Do.

I 67% solution of ethylene diamine.

mensions as under the tarnish removal test specifications given above are degreased with an alkaline metal cleaner and then dipped for seconds in a 10% sulfuric acid solution at room temperature, in order to remove any tarnish. The so-treated brass specimens are then subjected to a one hour burnishing treatment in the rubber-lined tumbling barrel described above. Average initial and final reflectance readings are similarly obtained upon these so-treated samples. The increase in reflectance constitutes a measure of the efliciency of the burnishing action, and the presence or absence of a tarnish on the burnished specimen is visually observed in order to determine whether there has been a redeposition of tarnish from the burnishing treatment.

Several difierent alkyl amines in the amount of 2% were added to a 10% stock solution of wetting agent consisting of a sulfonated condensation product of an alcohol and higher fatty acid (Cerfak N-101). This stock solution was then made up into a burnishing solution at a concentration of one liquid ounce of stock solu- (Cerfak N-l00 or "Cerfak N-101) 10 Monoethanolamine 5 Ethylene diamine (67% solution) 2 Water Balance Example 2 Per cent Wetting agent, sodium salt of sulfonated glycerol-higher fatty acid monoester ("Arction per gallon of tap water. Results of tarnish tic Syntex M) 20 removal and luster tests upon such compositions Ethylene diamine (67% solution) 2 were as follows: Water 7 Balance Table I Temish Removal Test Luster Test 2% Allrylamine Addition a ga? wetting Agent Initial Final Reflect Initial Final Refleet- Appemm Reflect- Reflectancc Reileet- 'Ieilectancc anoe anoe increase ance anee Increase None 21.0 40.0 19.0 Monoethylamin l8. 5 38. 5 20.0 49. 0 75.5 Y 26. 5 Slight 'larnish. Triothylalnine 17.0 as. 0 21.0 42. 5 1a. 0 so. 5 Do. Monoamylamlne 21. 5 40. 5 19.0 42. 0 75.0 33. 0 Do. Ethylene Dlamine 1e. 5 67.0 41. 5 4a. 5 76.5 32. 5 Bright.

1 67% solution of ethylene diamine.

From the foregoing it will be seen that the alkyl Example 3 monoamines were unsatisfactory in that the did P nt not produce a suificient reflectance increase to remove tarnish in the first instance, and that in the luster tests, even though a substantial increase in reflectance was obtained, tarnish redeposition occurred. 0n the other hand, in the case of the alkylenepolyamine, namely ethylene 7 Water 70 Wetting agent, sodiumsalt of sulfonated glycerol-higher fatty acid monoester ("Arctic Syntex M) 20 Monoethanolamine 5 Ethylene diamine (67% solution) V Balance Wetting agent, sulfonated condensation product of an alcohol and a higher fatty acid ("Cerfak N-101") 10 Monoethanolamine 5 Propylene diamine Example 6 Per cent Wetting agent, sulfonated condensation product of an alcohol and a higher fatty acid ("Cerfak N-l'OO or "Cerfak Nll)- 10 Monoethanolamine Triethylene tetrarnine -i 2 Water alance The compositions of all the foregoing 'Examples 1 to 6, when employed at a concentration 'of approximately oneiliquid ounce per gallon=of aqueous solu'tion, in "a'ddition to satisfactorily meeting the tarnish removal and luster tests hereinabove described.havealso enjoyed excellerit tarnish remo al and'brihtening results in commercial burnishing operations.

Equivalent modes of practicing my invention may be followed provided that they are within the scope and purview of theappended claims.

I, therefore, distinctly claim and particularly point out as my invention:

l. The method of removing tarnish and polishing brass articles, which comprises ball-burnishing said articles in an aqueous solution containing 0.05%-0.1% by weight of a wetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

RCOOCHzCHOHCHzOSOsNa where RCOO represents a mixed coconut oil-fatty acid radical and the sodium salt of sulfated lauryl alcohol; and 0.005%-0.05% of ethylene diamine.

2. The method of removing tarnish and polishing brass articles, which comprises ball-burnishing said articles in an aqueous solution containing 0.05 %-0.1% by weight of a wetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

RCOOCI-IzCHOHCHzOSOaNa where RCOO represents a mixed coconut oil-fatty acid radical and the sodium salt of sulfated lauryl alcohol; 0.005 %-0.05% of ethylene diamine, and 0.025 %-0.05% of monoethanolamine.

3. The method of removing tarnish and polishing brass articles, which comprises ball-burnishing said articles in an aqueous solution having a concentration of approximately one liquid ounce per gallon of a composition consisting of parts by weight of a wetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

acoocmcnoncmosoma where R000 represents a mixed coconut. oilfatty acid radical and the sodium salt of sulfated lauryl alcohol; 5 parts of monoethanolamine, 2 parts of ethylene diamine and a quantity sufllcient of water to make parts.

4. The method of removing tarnish and polishing brass articles, which comprises ball-burnishing said articles in an aqueous solution containing 0.05%-0.1% by weight of a wetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

RCOOCHzCHOHCHzOSOsNa where RCOO represents a mixed coconut 011-, fatty acid radical and the sodium salt of sulfated lauryl alcohol; and 0.005%-0.05% of an alkylenepolyamine selected from the group consisting of ethylene diamine, propylene diamine and triethylene tetramine.

5. A metal burnishing composition in liquid form consisting of 5-20 parts by weight of a wetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

RCOOGHzCHOHCHzOSOaNa where RCOO represents a mixed coconut oilfatty acid radical and'the sodium salt of sulfated lauryl alcohol; and 44 -2 parts of an alkylenepolyamine selected from the group consisting of ethylene diamine, propylene diamine and triethylene tetramine; and the balance consisting essentially of water.

6. A metal burnishing composition in liquid form consisting of 5-20 parts by weight of awetting agent selected from the group consisting of the sodium salt of sulfonated glycerol-higher fatty acid mono-ester corresponding to the formula:

RCOOCHzCHOHCHzOSOzNa noocmcnoncmosoma where RCOO represents a mixed coconut oilfatty acid radical and the sodium salt ofsulfated lauryl alcohol; and -2 parts of ethylene diamine, the balance consisting essentially of water.

8. A metal burnishing composition in liquid form consisting of 20% by weight of thesodium salt of sulfonated-glycerol higher fatty acid mono-ester corresponding to the formula:

RCOOCHzCHOHCHrOSOaNa where RCOO represents a mixed coconut oilfatty acid radical; 5% of monoethanolamine. /g% of ethylene diamine solution of 67% strength, and the balance water.

LOWELL R. MCCOY.

(References, on following Page):

w 7 8 REFERENCES CITED Number Name Date The following references are of record in the 1368324 Bert-sch July 1934 m of t t 2,049.4 7 Mnookin Aug. 4, 1936 STA S PATENTS 2,089,212 Kritchevsky Aug. 10, 1937 N be Date 5 OTHER REFERENCES um I Sy thetic Organic Chem1ca1sBooklet of Car- 1,063,478 Uebersax June 3, 1913 m d 0 29 tt 12 1932 e 83 Carbon C0rp., N. Y., 12th ed., 1945, page 1,945,908 Mascareno Feb. 6, 1934 

1. THE METHOD REMOVING TARNISH AND POLISHING BRASS ARTICLES, WHICH COMPRISES BALL-BURNISHING SAID ARTICLES IN AN AQUEOUS SOLUTION CONTAINING 0.05%-0.1% BY WEIGHT OF A WETTING AGENT SELECTED FROM THE GROUP CONSISTING OF THE SODIUM SALT OF SULFONATED GLYCEROL-HIGHER FATTY ACID MONO-ESTER CORRESPONDING TO THE FORMULA: 